3D interconnected network architectures assembled from W18O49 and Ti3C2 MXene with excellent electrochemical properties and CDI performance

Abstract

W18O49 has been demonstrated to be a promising candidate for efficient electrochemical applications. To further improve the electrical conductivity of W18O49 and make it suitable for hybrid capacitive deionization (HCDI), highly stable three-dimensional (3D) interconnected network architectures assembled from W18O49 and Ti3C2 MXene composites with different Ti3C2 contents have been synthesized via a facile and effective electrostatic attraction self-assembly strategy and used as a novel HCDI electrode material. Compared to single-component electrodes, the synergistic effect between W18O49 and Ti3C2 enabled high specific surface area (SSA), fast ion diffusion, and dual pseudocapacitance effect. These multiple advantages of the W18O49/Ti3C2 electrode achieved a preponderant salt adsorption capacity (SAC) as high as 29.25 mg g−1 in 500 mg L−1 NaCl solution at an applied voltage of 1.2 V. An excellent capacitance (153F g−1 at 2 mV s−1) and high cycling stability (maintaining 98.3% of the initial capacity after 10 cycles) were also observed. This work could provide some insights for rational design of 3D electrode architectures for electrochemical applications and water desalination.